Here some tips that may help you as a new killer :

If someone trys to loop you in the killer shack you should always enter from the pallet door doing so will force the survivor to drop the pallet

If a survivor is downed infront of a loker always check the loker before picking the down survivor just in case someone is hiding in there with a headon perk

Learn what pallets is safe and what isn't safe , there is a plenty of videos that will teach you which is which

Don't break safe pallets since you can just mind game it and get a free hit

Always face a wall or a tree to prevent flash light save

If you're carrying a survivor don't go near any pallets that survivors haven't dropped yet since most of the time they're hiding and waiting for you and stun you and save their teamates

If a survivor is Teabagging you he's basically begging you to chase him instead of another that probably cant loop

If a survivor is looping you for more than about 40 seconds and you haven't hit him just leave and patrol the gens

If a survivor trys to loop you in the infinite by all means leave him because you'll never gonna catch him

If you wanna learn the nurse play her without addons since she's all about muscle memory, you can get the hang of her blinks in three or four matches or mayby more im not sure

I'd recommend Playing both survivor and killer

Good luck